The present invention relates to a fuel supply apparatus or supplying a fuel to an engine using a fuel pump disposed in a fuel tank.
Hitherto, a apparatus described in the International Publication No.WO96/23966 has been known as a fuel supply apparatus for supplying a fuel to an engine. This apparatus is a unified construction in which a fuel pump is accommodated in a pump case through a rubber member, an intake filter is connected to an intake pipe of the fuel pump, a fuel filter for filtering a fuel discharged from the fuel pump is accommodated in a filter case, and the pump case and the filter case are engaged by snap-fitting.
However, in the -construction described in the International Publication No.WO96/23966, the intake pipe side of the fuel pump is exposed to outside from the pump case, and consequently, any noise generated on the intake side of the fuel pump is directly transmitted to the inside of the fuel tank. Such a noise is heard from outside of the fuel tank. The intake pipe of the fuel pump is approximately L-shaped, which is easy to generate a noise when the fuel is sucked. Moreover, the fuel pump and the pump case required to be positioned with respect to the rubber member and the intake pipe respectively, and therefore this apparatus is inferior in assembling efficiency.
The present invention was made to solve the above-discussed problems and has an object of obtaining an improved fuel supply apparatus of simple structure capable of reducing a noise generated when the fuel pump sucks a fuel.
A fuel supply apparatus according to the invention is a fuel supply apparatus for supplying a fuel to an engine comprising:
a fuel tank; a cylindrical fuel pump disposed in the mentioned fuel tank for raising a pressure of the fuel sucked from an intake port thereof and discharging the fuel from a discharge port thereof; an intake filter for filtering the fuel in the mentioned fuel tank and supplying the fuel to the intake port of the fuel pump; a pressure regulator for regulating a pressure of the fuel discharged from the discharge port of the mentioned fuel pump; and a holding case hermetically covering at least the intake port side of the fuel pump and accommodating, and holding the fuel pump. As a result of such construction, it is possible to reduce any noise generated when the fuel pump sucks the fuel and simplify the structure.
The holding case is provided with a first connecting portion to be connected to a fuel filter and a second connecting portion to be connected to the intake port of the fuel pump. As a result, it is possible to further reduce the noise generated when the fuel pump sucks the fuel. The intake port of the second connection portion of the holding case are connected through a bypass formed by a rubber member disposed in the holding case. As a result, it is not necessary to use special connecting pipe for connecting them, and number of parts can be reduced as to compare with prior apparatus.
The rubber member is interposed between the fuel pump and the holding case, and serves as a cushion for the mentioned fuel pump. As a result, the system is small-sized and the system is assembled easily.
The bypass is formed with a groove provided on the rubber member and an inner peripheral wall of the holding case, and the mentioned groove is formed to communicate to the second connecting portion of the holding case and to the intake port of the fuel pump. As a result, the system is assembled easily.
The rubber member is interposed between an outer circumference of the fuel pump and an inner circumference of the holding case and is provided with a partition for partitioning the bypass. As a result, only the fuel that has passed through the intake filter is supplied to the bypass, and the fuel is supplied stably.
The holding case hermetically accommodates the pressure regulator and is provided with a fuel holding portion for holding the fuel discharged from the pressure regulator and a flowing out portion for flowing out the fuel to the fuel tank when the fuel in the mentioned fuel holding portion exceeds a predetermined amount. As a result, it is possible to reduce the noise generated when the fuel passes through the pressure regulator.
The flowing out portion is formed into plural holes. As a result, it is possible to reduce the noise generated when the fuel is flowed out from these holes.